Single access flow-reversal catheter devices and methods

ABSTRACT

Embodiments herein include devices and methods directed toward creating reverse flow within a vessel and thereby providing protection against embolic debris. Embodiments comprise a catheter and a plurality of occluders that are expandable and adjustable within a lumen to create low-pressure areas that reroute blood flow and embolic debris therein.

CROSS-REFERENCE TO A RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.14/747,680, filed Jun. 23, 2015, which is a divisional of U.S.application Ser. No. 13/803,423, filed Mar. 14, 2013, now U.S. Pat. No.9,084,857, issued Jul. 21, 2015, which claims the priority benefit under35 U.S.C. §119(e) to U.S. Provisional Application No. 61/624,973, filedon Apr. 16, 2012, the contents of which are incorporated herein in theirentireties.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates generally to catheter devices and methodsfor protecting against embolic debris during vascular interventions.More particularly, the devices and methods described herein can be usedwith endovascular procedures in a mammalian body and achieve bloodflow-reversal within the arterial vasculature as well as blood returnwithout a venous return.

Discussion of the Related Art

Contralateral flow occurs when there are arterial vessels that are influid communication at two points, e.g. a proximal and distal location.When the fluid pressure in one arterial conduit drops, the pressure fromthe other arterial conduit can cause the blood from the other side toflow into this conduit. For example, the arterial side of the cerebralcirculatory system generally can be seen as divided into two sets ofcontralateral arteries, both sets originating from the aortic arch withone set feeding the left side of the brain and the other set feeding theright side. A large number of minor and major communicating vesselsconnect these contralateral arteries. As such, if the blood pressurebecomes low enough on a given side, the pressure on the contralateral issufficient to cause blood to flow across the communicating vessels andin a retrograde fashion towards the low-pressure source. Artificiallyand temporarily occluding the natural antegrade flow in a cerebralvessel and providing a low-pressure outlet for the blood can induce thisretrograde effect.

This effect can be particularly useful when treating an artery in ornear the cerebral vasculature, or in another vessel with similarcontralateral flow properties. Endovascular treatment of a blood vessel,which has a reduced diameter, for example, through the effects oflesions called atheroma or the occurrence of cancerous tumors, cangenerate free-floating debris. Such debris may cause damaging embolisms,and embolisms occurring in the brain are particularly dangerous. Byinducing retrograde flow across a lesion in a cerebral vessel, anydebris generated can be routed away from the brain.

Current devices that create reverse flow may be improved upon in avariety of respects. For example, some devices require withdrawal of thepatient's blood to create retrograde flow across a lesion, and thepatient's blood during this process is not conserved. Furthermore,current devices may not maintain continuous reverse flow but ratherintermittent reverse flow. Maintaining a continuous reverse flow ratherthan an intermittent reverse flow further minimizes the risk thatembolic debris will migrate toward the brain. Another current devicedoes conserve blood and does maintain constant flow. However, thisdevice requires multiple access sites within a patient's vasculature,which presents more risk to the patient and impacts ease of use for theclinician. Therefore, there is a need for endovascular devices andmethods that create reverse flow and protect against embolic debriswhile conserving the patient's blood and requiring only a singlevascular access site.

SUMMARY OF THE INVENTION

Described embodiments are directed toward endovascular devices andmethods to reverse blood flow, continuous or discontinuous, across atreatment site (e.g., lesion) and reroute blood within the vasculatureusing only a single vasculature access site.

According to one embodiment, a flow-reversal catheter device comprises acatheter, a first occluder at or near a distal end of the catheter, areturn port located proximally to the first occluder, a conduitconnecting a distal opening of the catheter to the return port, and amechanism configured to create a continuous pressure gradient so thatblood flows into the distal opening of the catheter, through theconduit, and exits through the return port. Such mechanisms can includea second occluder positioned proximal to the first occluder, an externalpump, and/or a drain container.

According to another embodiment, a method for reversing blood flow in avessel, such as an artery supplying blood to the brain, utilizing aflow-reversal catheter device is provided. Yet another embodimentcomprises a method for treatment of a cerebral vessel having a stenosisutilizing the flow-reversal catheter device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure and are incorporated in andconstitute a part of this specification, illustrate various embodiments,and together with the description serve to explain the principles of thedisclosure.

FIG. 1 illustrates schematic views of a flow-reversal catheter device;

FIGS. 2-4 illustrate a side view of various inflatable occluders;

FIGS. 5-9 illustrate a cross-sectional view of inflation lumenconfigurations;

FIGS. 10-13 illustrate a side view of various slide-actuated occluders;

FIG. 14 illustrates a side view of a flow-reversal catheter devicecomprising a second occluder;

FIG. 15 illustrates a side view of a flow-reversal catheter devicecomprising a second occluder and an external pump;

FIG. 16 illustrates a perspective view of a catheter comprising anexpandable outer sheath;

FIGS. 17-18 illustrate side views of various return ports;

FIGS. 19-20 illustrate side views of a flow-reversal catheter devicecomprising a second occluder and a side view of the same deployed in thecarotid artery;

FIG. 21 illustrates a cross-sectional view of a catheter devicecomprising a first occluder (not shown) coupled to catheter, a secondoccluder (not shown) coupled to a second occluder catheter, and anintroducer sheath;

FIGS. 22-23 illustrate side views of a flow-reversal catheter devicecomprising an external pump;

FIG. 24 illustrates a side view of a flow-reversal catheter devicecomprising a drain container;

FIGS. 25-26 illustrate a side view of a filter; and

FIGS. 27-28 illustrate side views of a flow-reversal catheter devicecomprising a third occluder.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Persons skilled in the art will readily appreciate that variousembodiments may be realized by any number of methods and apparatusesconfigured to perform the intended functions. Stated differently, othermethods and apparatuses may be incorporated herein to perform theintended functions. It should also be noted that the accompanyingdrawing figures referred to herein are not all drawn to scale, but maybe exaggerated to illustrate various embodiments, and in that regard,the drawing figures should not be construed as limiting. Althoughembodiments may be described in connection with various principles andbeliefs, the present disclosure should not be bound by theory.

The terms “downstream” or “antegrade” and “upstream” or “retrograde,”when used herein in relation to the patient's vasculature, referrespectively, to the direction of blood flow and the direction oppositethat of blood flow, respectively. In the arterial system, “downstream”or “antegrade” refers to the direction further from the heart, while“upstream” or “retrograde” refers to the direction closer to the heart.The terms “proximal” and “distal,” when used herein in relation to adevice or device component refer to directions closer to and fartheraway from the operator of the device. Since the present disclosure isnot limited to peripheral or central approaches, the device should notbe narrowly construed when using the terms proximal or distal sincedevice features may be slightly altered relative to the anatomicalfeatures and the device position relative thereto.

Described embodiments are directed toward endovascular devices andmethods to reverse blood flow, continuous or discontinuous, across atreatment site (e.g., lesion) and reroute blood within the vasculatureusing only a single vasculature access site. Embodiments herein aredirected toward rerouting embolic debris of a wide range of particlesizes away from particularly at-risk areas, such as the cerebrovascularsystem, during an endovascular treatment, and can further be configuredto filter embolic debris. These embodiments are configured to traversetortuous vessel anatomy, establish reverse flow across a treatment site,and provide a working lumen through which a clinician can deliver one ormore secondary endovascular devices.

As used herein, “embolic debris” means any biologic or non-biologicmass, the presence of which in the vasculature presents a risk,including, but not limited to, plaque, emboli, etc.

“Reverse flow,” as used herein, is the flow of blood opposite to thedirection of blood flow under normal blood flow conditions.Flow-reversal is achieved by creating a pressure gradient so blood flowis reversed and directed from the treatment site into lumen of catheterto be rerouted to another location. The pressure gradient can befacilitated by creating a low-pressure source(s), which can be withinthe catheter device itself or created in a desired location within thevasculature that is in fluid communication with the conduit of thecatheter device.

As mentioned previously, a purpose of reverse flow is to channel embolicdebris of a wide range of particle sizes away from particularly at-riskareas during an endovascular treatment. In accordance with anembodiment, blood, along with embolic debris in some embodiments, fromthe treatment site is rerouted through the catheter to another locationalong the delivery path. “Delivery path,” as used herein, is the path ofan endovascular device through the vasculature from an entry point to atreatment site. Along this path from high to low pressure, a filter canbe included to capture embolic debris from the blood.

A flow-reversal catheter device comprises: (i) a catheter havingproximal and distal ends with a lumen extending therethrough; (ii) afirst occluder at the distal end of catheter; (iii) a return portlocated proximally to first occluder; (iv) a conduit fluidly connectinga distal opening of catheter to return port; and (v) a mechanism (notshown) configured to create a pressure gradient so that blood flows intodistal opening, through conduit, and exits through return port. In oneembodiment, with reference to schematic FIG. 1, intended to showrelative positioning of the elements, a flow reversal catheter 100comprises (i) a catheter 110 having proximal and distal ends with alumen extending therethrough; (ii) a first occluder 120 at the distalend of catheter 110; (iii) a return port 130 located proximally to firstoccluder 120; (iv) a conduit 150 fluidly connecting a distal opening 112of catheter 110 to return port 130; and (v) a second occluder 170 thatis proximal the first occluder 120 and distal the return port 130.

In various embodiments, flow-reversal catheter device 100 is configuredsuch that a single site entry is all that is required to reroute blood,along with filtering and/or rerouting embolic debris. In other words,only a single pass of a medical device, namely flow-reversal catheterdevice 100, through the wall of access vessel is required. No otherentry point is required to reroute blood flowing into conduit to anotherlocation within the vasculature. In the case of an arterial sideprocedure, blood is rerouted to a location within the arterial side andaccess to the venous side, i.e., a venous return, is not employed. Assuch, return port 130 is locatable, during use of catheter device 100,at a point along the vasculature delivery path.

Catheter 110 is generally any elongated structure configured to providea working lumen through which blood and embolic debris can be channeledand/or through which one or more secondary endovascular devices (e.g., aballoon catheter, balloon wire, delivery catheter, drug delivery device,filters, stents, stent-grafts, diagnostic catheters, infusion catheters,aspiration catheters, or any other device configured to be deliveredand/or deployed through catheter 110) can be delivered through lumen ofcatheter 110. A catheter 110 comprises a proximal opening and a distalopening and comprises at least one lumen extending therethrough. Aproximal opening of catheter can connect to a catheter hub.

Catheter 110 can be configured to be bendable to traverse throughtortuous vasculature, and can further be configured to minimize oreliminate kinking. Catheter 110 can comprise an inner diameter ofsufficient size to permit passage of blood flow, a secondaryendovascular device, and optionally a third occluder described below.Catheter 110 can comprise an outer diameter of sufficient size to permitpassage through vasculature to access a treatment site. Catheter 110 cancomprise any medical-grade material. Catheter 110 can comprise polymericor metallic materials or combinations thereof. For example, catheter 110can comprise a polymeric film tube with spiral or braided nitinolreinforcements.

Typical materials used to construct catheter 110 can comprise commonlyknown materials such as Amorphous Commodity Thermoplastics that includePolymethyl Methacrylate (PMMA or Acrylic), Polystyrene (PS),Acrylonitrile Butadiene Styrene (ABS), Polyvinyl Chloride (PVC),Modified Polyethylene Terephthalate Glycol (PETG), Cellulose AcetateButyrate (CAB); Semi-Crystalline Commodity Plastics that includePolyethylene (PE), High Density Polyethylene (HDPE), Low DensityPolyethylene (LDPE or LLDPE), Polypropylene (PP), Polymethylpentene(PMP); Amorphous Engineering Thermoplastics that include Polycarbonate(PC), Polyphenylene Oxide (PPO), Modified Polyphenylene Oxide (Mod PPO),Polyphenylene Ether (PPE), Modified Polyphenylene Ether (Mod PPE),Thermoplastic Polyurethane (TPU); Semi-Crystalline EngineeringThermoplastics that include Polyamide (PA or Nylon), Polyoxymethylene(POM or Acetal), Polyethylene Terephthalate (PET, ThermoplasticPolyester), Polybutylene Terephthalate (PBT, Thermoplastic Polyester),Ultra High Molecular Weight Polyethylene (UHMW-PE); High PerformanceThermoplastics that include Polyimide (PI, Imidized Plastic), PolyamideImide (PAI, Imidized Plastic), Polybenzimidazole (PBI, ImidizedPlastic); Amorphous High Performance Thermoplastics that includePolysulfone (PSU), Polyetherimide (PEI), Polyether Sulfone (PES),Polyaryl Sulfone (PAS); Semi-Crystalline High Performance Thermoplasticsthat include Polyphenylene Sulfide (PPS), Polyetheretherketone (PEEK);and Semi-Crystalline High Performance Thermoplastics, Fluoropolymersthat include Fluorinated Ethylene Propylene (FEP), EthyleneChlorotrifluroethylene (ECTFE), Ethylene, Ethylene Tetrafluoroethylene(ETFE), Polychlortrifluoroethylene (PCTFE), Polytetrafluoroethylene(PTFE), expanded Polytetrafluoroethylene (ePTFE), PolyvinylideneFluoride (PVDF), Perfluoroalkoxy (PFA). Other commonly known medicalgrade materials include elastomeric organosilicon polymers, polyetherblock amide or thermoplastic copolyether (PEBAX) and metals such asstainless steel and nickel/titanium alloys.

In various embodiments, first occluder 120 comprises any radiallyexpandable and collapsible structure at the distal end of catheter 110and configured, when in an expanded state, to substantially block orpartially constrict the flow of blood about the periphery of catheter110 and thereby channel blood and emboli into distal opening 112. Firstoccluder 120 is delivered in a collapsed configuration and then expandedto block or constrict the flow of blood proximate a treatment site.

Blocking the flow of blood facilitates the reversal of blood flow acrossa treatment site. By way of example, expanding first occluder 120 in thecommon carotid artery blocks the flow through the common carotid arteryand causes the pressure on the downstream side, i.e., distal side offirst occluder 120, to drop, thereby facilitating blood fromcontralateral vessels to flow toward the lower pressure and flow intoconduit 150 hence sweeping embolic debris into distal opening 112 ofcatheter 110. Contralateral flow, once stabilized, maintains the bloodpressure on the downstream side flowing into distal opening 112 at about70 mmHg to about 90 mmHg.

First occluder 120 can be any shape which occludes a radial space aboutthe distal region or end of catheter 110, so as to ensure blood andemboli is directed into distal opening 112 of catheter 110 rather thanbecoming trapped between the intraluminal wall of the vessel and theouter wall of catheter 110. For example, first occluder 120 can bedisc-shaped, donut-shaped, cylindrical, cone-shaped (e.g., pear-shaped),funnel-shaped, or any other shape that substantially occludes the flowof blood about the radial space of the distal region of catheter 110 anddefine the outer wall of catheter 110 to permit blood to pass throughthe distal opening 112 of catheter 110.

First occluder 120 can transition between a collapsed configuration andan expanded configuration in any manner. For example, first occluder 120can be inflated, deflated, self-expanding, and/or slideably actuated.

With reference to FIGS. 2-9, a first occluder can comprise an inflatableoccluder 221, such as a balloon. Inflatable occluder 221 obtains itsexpanded configuration by passing a fluid through an inflation lumen222, and its collapsed configuration by withdrawing the fluid frominflatable occluder 221 through inflation lumen 222. Inflation lumen 222can be embedded within or longitudinally extending alongside the wall ofcatheter 210, or between the wall of catheter 210 and a coaxial outersheath or a secondary catheter 265. Cross-sectional views of variousconfigurations of inflation lumen 222 are illustrated in FIGS. 5-9.

Inflatable occluder 221 formation can be carried out in any conventionalmanner using known extrusion, injection molding and other moldingtechniques. Typically, there are three major steps in the process thatinclude extruding a tubular pre-form, molding inflatable occluder 221and annealing inflatable occluder 221. Depending on the method ofmanufacturing inflatable occluder 221, the pre-form can be axiallystretched before it is blown. Techniques for inflatable occluder 221formation are described in U.S. Pat. No. 4,490,421 to Levy; RE32,983 toLevy; RE33,561 to Levy; and U.S. Pat. No. 5,348,538 to Wang et al., allof which are hereby incorporated by reference.

Inflatable occluder 221 can be formed from using any materials known tothose of skill in the art. Commonly employed materials include thethermoplastic elastomeric and non-elastomeric polymers and thethermosets including the moisture curable polymers. Examples of suitablematerials include but are not limited to, polyolefins, polyesters,polyurethanes, polyamides, polyimides, polycarbonates, polyphenylenesulfides, polyphenylene oxides, polyethers, silicones, polycarbonates,styrenic polymers, copolymers thereof, and mixtures thereof. Some ofthese classes are available both as thermosets and as thermoplasticpolymers. See U.S. Pat. No. 5,500,181 to Wang et al., for example, whichis hereby incorporated by reference. As used herein, the term“copolymer” shall be used to refer to any polymer formed from two ormore monomers, e.g., 2, 3, 4, 5, etc.

Useful polyamides include, but are not limited to, nylon 12, nylon 11,nylon 9, nylon 6/9 and nylon 6/6. The use of such materials is describedin U.S. Pat. No. 4,906,244 to Pinchuk et al., for example, which ishereby incorporated by reference.

Examples of some copolymers of such materials include thepolyether-block-amides, available from Elf Atochem North America inPhiladelphia, Pa. under the trade name of PEBAX®. Another suitablecopolymer is a polyetheresteramide.

Suitable polyester copolymers include, for example, polyethyleneterephthalate and polybutylene terephthalate, polyester ethers andpolyester elastomer copolymers such as those available from DuPont inWilmington, Del. under the trade name of HYTREL®.

Block copolymer elastomers such as those copolymers having styrene endblocks, and midblocks formed from butadiene, isoprene,ethylene/butylene, ethylene/propene, and so forth can be employedherein. Other styrenic block copolymers include acrylonitrile-styreneand acrylonitrile-butadiene-styrene block copolymers. Also, blockcopolymer thermoplastic elastomers in which the block copolymer is madeup of hard segments of a polyester or polyamide and soft segments ofpolyether can be employed herein.

Specific examples of polyester/polyether block copolymers arepoly(butylene terephthalate)-block-poly(tetramethylene oxide) polymerssuch as ARNITEL® EM 740, available from DSM Engineering Plastics andHYTREL® polymers available from DuPont de Nemours & Co, alreadymentioned above.

Suitable materials that can be employed in inflatable occluder 221formation are further described in, for example, U.S. Pat. No. 6,406,457to Wang et al.; U.S. Pat. No. 6,284,333 to Wang et al.; U.S. Pat. No.6,171,278 to Wang et al.; U.S. Pat. No. 6,146,356 to Wang et al.; U.S.Pat. No. 5,951,941 to Wang et al.; U.S. Pat. No. 5,830,182 to Wang etal.; U.S. Pat. No. 5,556,383 to Wang et al.; U.S. Pat. No. 5,447,497 toSogard et al.; U.S. Pat. No. 5,403,340 to Wang et al.; U.S. Pat. No.5,348,538 to Wang et al.; and U.S. Pat. No. 5,330,428 to Wang et al.,all of which are hereby incorporated by reference.

The above materials are intended for illustrative purposes only, and notas a limitation on the scope of the present disclosure. Suitablepolymeric materials available for use are vast and too numerous to belisted herein and are known to those of ordinary skill in the art.

With reference to FIGS. 10-13, a first occluder can comprise aslide-actuated occluder 223, such as an expandable mesh, braided, orribbed (e.g., malecot-type) structure which radially expands uponapplication of a longitudinal compression force and collapses uponapplication of a longitudinal tension force. Slide-actuated occluder 223can be attached at or near the distal end of catheter 210 and attachedto an actuating member (e.g., outer tube or semi-rigid longitudinalconnector) on its proximal end, or vice versa, wherein the actuatingmember is slidably coupled to catheter 210. Slide-actuated occluder 223can comprise any medical grade material, such as a polymeric or metallicmaterial.

Slide-actuated occluder 223 can comprise a covering, such as anelastomeric polymer film, to block or constrict blood flow. The coveringcan be elastic so that it stretches as the space between the braidedfilaments or ribs separates during radial expansion. Alternatively, atightly knit mesh or the like with or without a covering can block orconstrict blood flow.

Referring back to FIG. 1, first occluder 120 can be attached to catheter110 by various bonding techniques. Examples include, but are not limitedto, solvent bonding, thermal adhesive bonding and heat shrinking orsealing. The selection of the bonding technique is dependent upon thematerials from which the occluder and catheter are prepared. Forexample, U.S. Pat. No. 7,048,713 to Wang, which is hereby incorporatedby reference, provides for general teachings relating to the bonding ofan inflatable occluder to a catheter. Such modes of catheter attachmentcan be similarly applied to the second occluder and third occluderdescribed below.

With reference to FIGS. 14-15, conduit 350, the path of which isdepicted by the arrows in the referenced figures, comprises anystructure that provides a blood flow pathway between distal opening 312of catheter 310 and return port 330. Blood and embolic debris enterconduit 350 at distal opening 312 and flow down the pressure gradienttoward return port 330, where blood is reintroduced to a region in theaccess vessel proximal to first occluder 320 as well as a secondoccluder 370, if present. As such, conduit 350 comprises at least aportion of catheter 310.

During use, conduit 350 can be fully contained within the vasculaturealong the delivery path. For example, the entire length of conduit 350can consist of at least a portion of catheter 310. Alternatively,conduit can extend beyond catheter 310. For example, blood can exit theproximal opening of catheter 310 and enter into additional tubing 351 atcatheter hub 314. Blood can reenter the arterial vessel at theintroducer sheath hub 361 and pass into the interstitial space betweencatheter 310 and an introducer sheath 360 to be reintroduced into thevasculature at return port 330.

Additional tubing 351 of conduit 350 can comprise any structure thatprovides additional lumen to connect catheter 310 to return port 330.For example, conduit 350 can comprise tube(s), coupling(s), valve(s),catheter hub(s), or any other lumen-providing or lumen-connectingstructure.

With reference to FIG. 16, at least a portion of conduit 350 can beconfigured to be expandable with an increase in pressure. For example,catheter 310 can be delivered at a first profile and then when bloodbegins to flow into its lumen, catheter 310 expands with this increasein fluid pressure to a second diameter profile that is greater than thefirst diameter profile. Catheter 310 can comprise an expandable outersheath 311 concentric about an inner catheter. In this embodiment, bloodwill flow between catheter 313 and expandable outer sheath 311, causingouter sheath 311 to expand radially. In addition, a first occluder canbe configured to expand catheter 310 to the second profile. In thiscase, the first occluder would be discontinuous across distal opening312 of catheter 310 to allow for perfusion of blood.

With reference back to FIG. 14-15, flow-reversal catheter device 100 canfurther comprise introducer sheath 360. Introducer sheath 360 comprisesa distal and proximal end with a lumen therethrough and can beconfigured to serve as an access port into the vasculature forendovascular devices such as catheter 110 and/or the second occludercatheter 365. The proximal end of introducer sheath 360 can be coupledto introducer sheath hub 361. Introducer sheath hub 361 can be alsocoupled to additional tubing 351 to fluidly connect conduit 350 toreturn port 330.

With reference to FIGS. 17-18, return port 430 in various embodimentscomprises an opening through which blood exits flow-reversal catheterdevice 400. During use, return port 430 is locatable within the accessvessel proximal to the first occluder (not shown) as well as secondoccluder 470, if present. For example, return port 430 can comprise anopening in catheter wall (or second occluder catheter wall discussedbelow), an opening in introducer sheath 460 wall, the distal end oropening of the introducer sheath 460, and/or an opening along any otherportion of the conduit 450 along vasculature delivery path proximal thefirst occluder.

The flow-reversal catheter device further comprises a mechanism tocreate a pressure gradient, e.g., a low-pressure source that causesblood to flow along the conduit from the distal opening of the catheterto exit out the return port. A mechanism can be configured to provide acontinuous pressure gradient, or the pressure gradient can be providedat on-demand, pre-programmed, regular, or intermittent intervals.

For example, with reference to FIGS. 19-20, this mechanism can comprisea second occluder 570 similarly configured like first occluder 520 tosubstantially block or partially constrict blood flow and to create alow-pressure source (e.g., less than about 30 mmHg) on the downstreamside of second occluder 570. As such, return port 530, during use, islocatable in this downstream-occluded region. In the case of a procedurein the carotid artery or an artery distal thereto, as illustrated inFIG. 19, second occluder 570 can be locatable anywhere along thedelivery path (as that term has been defined herein) within or proximalthe aortic arch, such as downstream from the left common carotid artery.Constricting downstream of the aortic arch with second occluder 570 incombination with first occluder 520 inflated at the treatment site canincrease the pressure of the blood flowing into the common carotidartery opposite the side being treated.

Second occluder 570 can comprise any collapsible and expandablestructure of any shape that occludes or constricts a radial space aboutcatheter device 500 and is locatable proximal first occluder 520. In anembodiment, the length of catheter 510 between the first occluder 520and second occluder 570 can be greater than the distance between thetreatment site and a location along delivery path downstream of the leftsubclavian artery. For example, second occluder 570 can be deployed at alocation downstream of the renal arteries or a location downstream ofthe internal iliac arteries. Second occluder 570 can be coupled tocatheter 510, introducer sheath, or a second occluder catheter 565 thatslideably fits over catheter 510. Similar to first occluder 520described above, second occluder 570 can comprise an inflatable occluderor a slide-actuated occluder.

FIG. 21 illustrates a cross-sectional view of a catheter device 500comprising a first occluder (not shown) coupled to catheter 510; asecond occluder (not shown) coupled to a second occluder catheter 565;and an introducer sheath 560. Catheter 510 comprises an inflation lumen522 within the wall of catheter 510 and contains a secondaryendovascular device 519 within conduit 550. Second occluder catheter 565comprises an inner and outer tube with an inflation lumen 566 in theintermediate space.

With reference to FIGS. 22-23, another mechanism for creating a pressuregradient along conduit 650 can comprise an external pump 680. Forexample, external pump 680 can comprise a valved aspirator or syringeconnected to conduit 650 and can serve to aspirate blood from catheter610 to create reverse flow, and then valve(s) 681 are switched to pushaspirated blood towards return port 630. Other external pumps 680 caninclude a motorized pumps, such as a roller pump.

With reference to FIG. 24, a mechanism to create a pressure gradient cancomprise a drain container 785, such as an IV bag, wherein draincontainer 785 being at ambient pressure creates reverse flow. In variousembodiments, blood flowing into catheter 710 and through conduit 750will flow into drain container 785. Once the procedure is finished orwhile the procedure is ongoing, the blood in drain container 785 can beconnected to conduit 750 so that blood is returned to the vasculaturevia return port 730.

With reference to FIGS. 25-26, catheter device 800 can comprise filter890. Filter 890 can be locatable in line of conduit 850 or about oracross return port 830. Filter 890 comprises any device configured tocapture embolic degree, such as embolic debris having a size greaterthan about 50 μm or greater than about 100 μm. Filter 890 can beconfigured so that it can be visibly inspected during the procedure. Forexample, filter can be housed in a transparent or translucent section ofconduit 850. In addition, filter 890 can also be configured so that itcan be removed, cleaned, or replaced during the procedure, so that theamount of embolic debris can be routinely checked. Various embodimentsof filter 890 can comprise a net, mesh basket, screen, or the like.

A flow-reversal catheter device can comprise a single or a plurality ofmechanisms to create a pressure gradient along the conduit. For example,a second occluder, an external pump, and a drain container can becombined within a flow-reversal catheter device to create a pressuregradient along the conduit.

When a treatment site is in the location of a vessel bifurcation, suchas the common carotid artery bifurcation, flow-reversal can be enhancedby occluding the main vessel as well as the branch vessel not beingtreated. This will further ensure that blood flow when reversed willflow into the conduit rather than flowing into the branch vessel. Forexample, with reference to FIGS. 27-28, flow-reversal catheter device900 can comprise a third occluder 990. In the case of treating a lesionin the internal carotid artery, the common carotid artery will beoccluded with first occluder 920 and the external carotid artery can beoccluded by third occluder 990.

Similar to a first and second occluder, third occluder 990 comprises anyradially expandable and collapsible structure and is configured tosubstantially block the flow of blood through a vessel when in anexpanded state. Third occluder 990 is delivered in a collapsedconfiguration and then expanded to block the flow of blood in a branchvessel, such as the external carotid artery (ECA), as illustrated inFIG. 19. Third occluder 990 can comprise an inflatable occluder or aslide-actuated occluder as described above.

With reference to FIG. 28, third occluder 990 can comprise a balloonwire 991, which is deliverable through catheter 910 to occlude a branchvessel. Balloon wire 991 comprises an elongate member 992, such as ahypotube, with an expandable and collapsible occluder coupled to thedistal region thereof. Elongate member can comprise a lumen to inflateand deflate an inflatable occluder or be configured to actuate slideablya slide-actuated occluder into expanded or collapsed configurations.Alternatively, with reference to FIG. 27, catheter 910 can comprise adistally projecting strut 994 having a third occluder 990, which isconfigured so that blood can still flow into distal opening 912 ofcatheter 910 and into conduit 950.

Flow-reversal catheter device can be configured so that the distancebetween first, second, and/or third occluders, when present, isadjustable. For example, first, second, and/or third occluders can betelescopic relative to each other such that the catheter(s) or elongatemember(s) to which each is coupled is slideably coupled to the othercatheter(s) or elongate member(s). Furthermore, first, second, and/orthird occluders can comprise a radio-opaque marker to facilitatelocating the occluder in situ.

Similarly, first, second, and/or third occluders, when present, can beconfigured for adjustable attachment to the catheter body. The firstoccluder and/or the second occluder can be configured for adjustableattachment on a catheter or an introducer sheath. Adjustable attachmentincludes the ability of the user to move an occluder along a catheterand attach at a desired location on the catheter. This can include theability to disengage attachment and reengage attachment.

The respective size of each occluder is sufficient to occlude thetargeted vessel. For example, in an embodiment, the first occluder canocclude the common carotid artery and can be sized as such. The secondoccluder can occlude the descending thoracic aorta, common iliac artery,or the abdominal aorta and can be sized as such. The third occluder canocclude a branch vessel such as the internal or external carotid arteryand can be sized as such.

A catheter device can further comprise a therapeutic agent, such asheparin. For example, heparin can be imbibed on inner surface of acatheter or on a filter to prevent or minimize any clotting as bloodtravels through device toward the return port.

A method for reversing blood flow in a vessel, such as an arterysupplying blood to the brain—utilizing a flow-reversal catheter deviceas described herein comprising a second occluder—can comprise the stepsof locating a first occluder in an artery supplying blood to the brain;locating a second occluder in an artery so as to lower the pressure at areturn port upon expansion of the second occluder, e.g., such locationcan be downstream of the left common carotid artery; and expanding thefirst and second occluders whereby blood flows through the conduit froma distal end of the catheter to the return port. The method can furthercomprise the step of filtering blood from the conduit to remove embolicdebris therein. The second occluder can be substituted for or augmentedwith another mechanism configured to create a pressure gradient. If,instead of flowing through the conduit, the reversed blood flow isflowing into a branch vessel, a third occluder can be deployed distalthe first occluder within the branch vessel to occlude the branchvessel.

Methods for treatment of a cerebral vessel having a stenosis utilizingthe flow-reversal catheter device are described. The lumen of thecerebral vessel is accessed in one of three ways, depending on thelocation of the stenosis. Lesions in the distal posterior circulationwould be approached by a cut down to the vertebral artery. Lesions inthe distal anterior circulation would be approached percutaneouslythrough the common carotid arteries. Proximal lesions in all vesselswould be approached percutaneously through the femoral artery. In eachcase, after vasculature is accessed, a conventional guidewire is passedwithin the lumen of the cerebral vessel. Next, the distal end of thecatheter is introduced over the guidewire into the cerebral vesselstopping proximal to the lesion. The first occluder is inflated untilthe vessel is occluded. This can be determined by fluoroscopicvisualization of the stagnant flow or by gentle traction on thecatheter. Once reverse flow is confirmed, the interventional componentcan be inserted through the lumen and the lesion treated. Retrogradeblood flow will flush blood and debris through the conduit and to thefilter, if present, and then returned via the blood return port.Finally, the interventional device and then the catheter device areremoved.

These methods of using the catheter device disclosed herein serve asexamples and are not limiting. Further uses will be recognized by askilled artisan. For example, the creation of a low-pressure sitethrough arterial restriction can be anywhere along the path of thecatheter body, e.g., aorta, iliac, or femoral sites can be used.

EXAMPLE By way of Example, one Embodiment of a Catheter System can bemade and used as Follows

A first occluder and a catheter are commercially available from Gore'sFlow Reversal System. The catheter can be 6 Fr. stent deliverycompatible with approximately a 0.120″ OD and approximately 93 cmworking length. The first occluder can comprise a compliant balloon forocclusion of vessels from about 5 to about 12 mm. An external filter setsupplied with Gore's Flow Reversal System can also be utilized asadditional conduit to filter embolic debris from rerouted blood.

A second occluder and a second occluder catheter, which fit over theabove-described catheter, can comprise an outer tube slideably coupledover an inner tube with a compliant balloon attached to the outer tube,which is inflated via an inflation lumen residing in between the innertube and the outer tube. The inner tube slidably fits over the catheterand can have an inner diameter of 0.125″, an outer diameter of 0.140″and a length of 47 cm. The inner tube can be made of Pebax 7233. Theouter tube has a sufficient annular space to slide over the inner tubeto form an inflation lumen therebetween. For example, the outer tube canhave an inner diameter of 0.150″, an outer diameter of 0.166″ and alength of 41 cm (body stock) plus 1.5 cm (tip material). The outer tubecan also be made of Pebax 7233. The compliant balloon is commerciallyavailable from Advanced Polymers Inc. (API #30000000JA) and made fromurethane having low durometer. The dimension of the compliant ballooncan comprise a 28 mm diameter, a 30 mm length, and a neck inner diameterof approximately 0.150″, with the ability to be stretched over the0.166″ outer tube. The second catheter is connected to a hub, which iscommercially available from Qosina, and has a polycarbonate Y-arm (bothfemale luer connections) drilled thru with a 0.145″ and tip drilled to0.170″. In order to bond second catheter to hub and to assemble secondoccluder/second occluder catheter, a UV cure adhesive can be used, suchas Dymax 208 CTH, commercially available from DYMAX Corporation,Torrington, Conn. Stepwise instructions for the assembly are providedbelow.

An introducer sheath, which fits over second catheter, is commerciallyavailable from COOK having a 14 Fr. sheath size, 20 cm total length, anda side port for flushing (flexible extension).

Third Occluder, which is deliverable through the lumen of the catheter,can comprise the external carotid occlusion balloon wire supplied withGore's Flow Reversal system.

A secondary endovascular device, which is deliverable through the lumenof the catheter to the treatment site, can comprise a carotid stent. Inorder to assemble the second occluder/second occluder catheter, thefirst step is to trim both necks of compliant balloon to approximately 1cm in length. Next, position outer tube (body stock) over anapproximately 0.148″, Polytetrafluoroethylene (PTFE) coated stainlesssteel mandrel. Once in position, place a few drops of Dymax 208CTHaround the circumference of distal end of the outer tube, and slide theproximal neck of the compliant balloon over the outer tube to providefor approximately a 1 cm bond length. Wipe off excess adhesive, and UVcure for approximately 15 seconds. To connect the distal neck of theballoon to the outer tube, place a few drops of Dymax 208CTH around thecircumference of the proximal end of the outer tube (tip section), andslide the distal neck of the compliant balloon over the proximal end ofthe tip section of the outer tube to provide approximately 1 cm ofbonding area and approximately 1 cm for tip forming. Again, wipe offexcess adhesive, and UV cure for approximately 15 seconds. Once cured,remove the outer tube and compliant balloon assembly from mandrel. Inorder to connect to this assembly to the inner tube, place the innertube on an approximately 0.122″ PTFE coated stainless steel mandrel, andslide the inner tube through the outer tube plus balloon, aligning theend of the inner tube with the distal end of the outer tip tubing. Oncein position, apply Dymax 208CTH into the annular space of tip (gapbetween inner tube and outer tip section) and UV cure for approximately15 seconds. This should successfully seal off the annular space from anyleak paths. Once cured, trim proximal end of assembly so that inner tubesticks out of outer tube by approximately 2.5 cm. Prepare apolycarbonate y-arm from Qosina with a large enough size to accommodatethe second catheter by first drilling out the main lumen of the hub toaccommodate the inner tubing (˜0.145″). Then, drill out distal end ofy-arm to accommodate the outer tubing up to inflation port (0.170″drill, 1 cm deep). When drilling is complete, position hub over theproximal end of the assembly and glue with Dymax 208CTH. UV cure forapproximately 15 sec per glue location, and remove from the mandrel.

In order to use the above-described embodiment of the catheter system,prepare the first occluder and the catheter; the second occluder and thesecond occluder catheter; and the introducer sheath in accordance withany supplied instructions for use, which includes flushing all catheterswith saline to remove air prior to use. Once prep work is complete,access to the patient's femoral artery is established with the 14 Fr.introducer sheath. The second occluder catheter is then slid through thelumen of introducer sheath so that the second occluder is in a suitablelocation, such as the iliac or aorta. Next, the catheter is passed thruthe lumen of second occluder catheter and the first occluder ispositioned in the Common Carotid Artery (CCA). Once occluder positionsare set, the external filter set is connected to the blood exit port ofthe catheter and to the side port of the introducer sheath. A 3-wayvalve can be utilized, if needed. Next, the third occluder is guidedthru the main lumen of the catheter to a suitable location in theExternal Carotid Artery (ECA) followed by the secondary endovasculardevice, e.g., stent, to be staged proximal the location to be treated.

From here, the occluders are inflated. First, the third occluder of theexternal balloon wire is inflated in the ECA, and then the firstoccluder in the CCA. Inflate the second occluder in the appropriatelocation, iliac or aorta as noted above. If necessary, the secondoccluder can be repositioned by sliding second occluder catheter alongcatheter such as to prevent occlusion of critical arteries (e.g., renalarteries). Once all occluders are inflated, the clinician will ensureblood is flowing out of the exit port from the catheter, through theexternal filter set, and returning to the patient's arterial side viathe side port of the introducer sheath.

Once reverse flow is established, the Carotid Artery procedure,utilizing the secondary endovascular device, is performed. When nofurther manipulations are needed about the treated lesion, the mainconduit is aspirated. The filter can be inspected for embolic debris atthis point or at any other point during the procedure. The occluders arethen deflated, and the catheter system is removed.

In addition to being directed to the teachings described above andclaimed below, devices and/or methods having different combinations ofthe features described above and claimed below are contemplated. Assuch, the description is also directed to other devices and/or methodshaving any other possible combination of the dependent features claimedbelow.

Numerous characteristics and advantages have been set forth in thepreceding description, including various alternatives together withdetails of the structure and function of the devices and/or methods. Thedisclosure is intended as illustrative only and as such is not intendedto be exhaustive. It will be evident to those skilled in the art thatvarious modifications can be made, especially in matters of structure,materials, elements, components, shape, size and arrangement of partsincluding combinations within the principles of the invention, to thefull extent indicated by the broad, general meaning of the terms inwhich the appended claims are expressed. To the extent that thesevarious modifications do not depart from the spirit and scope of theappended claims, they are intended to be encompassed therein.

What is claimed is:
 1. A single-access catheter device comprising: afirst catheter having a proximal and distal region with a lumentherethrough; a first occluder located within the distal region of thefirst catheter; an introducer sheath having a proximal and distal regionwith a lumen through which the first catheter passes; a second occluderlocated on the introducer sheath and located proximal to the firstoccluder; a return port located proximal to the second occluder; and aconduit connecting a distal end of the first catheter to the returnport.
 2. The device of claim 1, wherein the return port furthercomprises an opening in the wall of the introducer sheath.
 3. The deviceof claim 1, wherein, when the first occluder is expanded in a vessel, apressure gradient causes blood to flow into the conduit through thedistal end of the first catheter.
 4. The device of claim 3, wherein theconduit comprises at least a portion of the interstitial space betweenthe introducer sheath and the first catheter.
 5. A single-accesscatheter device comprising: a first catheter having a proximal anddistal region with a lumen therethrough; a first occluder located withinthe distal region of the first catheter; a second occluder locatedproximal to the first occluder; a return port located proximal to thesecond occluder; and a conduit connecting a distal end of first catheterto the return port, wherein the return port comprises an opening locatedin a wall of the first catheter.
 6. The device of claim 5, furthercomprising an introducer sheath, wherein the return port furthercomprises an opening in the wall of the introducer sheath.
 7. The deviceof claim 5, wherein, when the first occluder is expanded in a vessel, apressure gradient causes blood to flow into the conduit through thedistal end of the first catheter.
 8. A single-access catheter devicecomprising: a first catheter having a proximal and distal region with alumen therethrough; a first occluder located within the distal region ofthe first catheter; a second occluder located within the proximal regionof the first catheter; a return port located proximal to the secondoccluder; and a conduit connecting a distal end of the catheter to thereturn port, wherein the second occluder is located on the firstcatheter.
 9. The device of claim 8, wherein a position of the secondoccluder within the first catheter is adjustable.
 10. The device ofclaim 8, wherein, when the first occluder is expanded in a vessel, apressure gradient causes blood to flow into the conduit through thedistal end of the first catheter.